/Engine/Source/Editor/LevelEditor/Public/LevelEditorOutlinerSettings.h
Delegate to create a Filter for the Outliner
typedef TBaseDelegate_NoParams< [TSharedPtr](API\Runtime\Core\Templates\TSharedPtr)< [FFilterBase](API\Developer\ToolWidgets\Filters\FFilterBase)< const [ISceneOutlinerTreeItem](API\Editor\SceneOutliner\ISceneOutlinerTreeItem) & > > > FOutlinerFilterFactory